restructured code

in an attempt to understand the codebase, i restructured it, so that's things can found more easily.
mainly, there are css resources moved into a resource directory and all templates in the templates directory.
the upgrade steps are removed, because simply importing the profile should be enough.
plus, everything follows pep8.
it should not break existing code, except templates or resources were overwritten via z3c.jbot.

@bosim @fredvd do you agree with these changes?